Predictors of PrEP awareness, PrEP discussion and interest in long‐acting injectable PrEP among Filipina transfeminine adults

Abstract Introduction Transfeminine adults are impacted by the HIV epidemic in the Philippines, and newly approved modalities of pre‐exposure prophylaxis (PrEP), including long‐acting injectable (LAI‐PrEP), could be beneficial for this group. To inform implementation, we analysed PrEP awareness, discussion and interest in taking LAI‐PrEP among Filipina transfeminine adults. Methods We utilized secondary data from the #ParaSaAtin survey that sampled Filipina transfeminine adults (n = 139) and conducted a series of multivariable logistic regressions with lasso selection to explore factors independently associated with PrEP outcomes, including awareness, discussion with trans friends and interest in LAI‐PrEP. Results Overall, 53% of Filipina transfeminine respondents were aware of PrEP, 39% had discussed PrEP with their trans friends and 73% were interested in LAI‐PrEP. PrEP awareness was associated with being non‐Catholic (p = 0.017), having previously been HIV tested (p = 0.023), discussing HIV services with a provider (p<0.001) and having high HIV knowledge (p = 0.021). Discussing PrEP with friends was associated with older age (p = 0.040), having experienced healthcare discrimination due to transgender identity (p = 0.044), having HIV tested (p = 0.001) and having discussed HIV services with a provider (p < 0.001). Very interested in LAI‐PrEP was associated with living in Central Visayas (p = 0.045), having discussed HIV services with a provider (p = 0.001) and having discussed HIV services with a sexual partner (p = 0.008). Conclusions Implementing LAI‐PrEP in the Philippines requires addressing systemic improvements across personal, interpersonal, social and structural levels in healthcare access, including efforts to create healthcare settings and environments with providers who are trained and competent in transgender health and can address the social and structural drivers of trans health inequities, including HIV and barriers to LAI‐PrEP.


I N T R O D U C T I O N
Transfeminine adults are disproportionately impacted by the growing HIV epidemic in the Philippines [1]. Based on successful findings from an in-country pre-exposure prophylaxis (PrEP) demonstration study showing clinical effectiveness [2], the Philippines' Department of Health recently approved tenofovir/emtricitabine as daily oral PrEP for HIV prevention [3]. Updated national clinical guidelines now recognize PrEP as part of its national essential medicine formulary as of January 2022 [3], and recommend the urgent need to deliver it to populations placed vulnerably to HIV infection, including Filipina transfeminine adults who are bearing the brunt of the epidemic-with HIV prevalence approximately doubling (3.9% in 2020 vs. 1.7% in 2018) within a short timeline [1,4]. Moreover, with several new PrEP modalities in the clinical trial pipeline, like long-acting injectable pre-exposure prophylaxes (LAI-PrEP) [5,6], understanding how LAI-PrEP would fit into the lives of this population is necessary for the future incountry PrEP implementation programming.
Determinants of PrEP implementation are multilevel [7], and frequent barriers included factors (1) at the personal level-lack of PrEP awareness and knowledge [8-11]; (2) at the interpersonal level-discomfort talking to providers about PrEP, provider's lack of knowledge or support of PrEP and having mistrust of providers [12][13][14]; (3) at the social level-lack of communication about PrEP among community members [14,15,16], including PrEP discussion among trans friends and providers [14]; and (4) at the structural levelhaving segregated or fragmented healthcare systems, concern about paying for PrEP, including out-of-pocket costs, stigma and discriminatory practices and policies related to PrEP, HIV, transgender identity and sexual behaviour, as well structural determinants, such as poverty, unemployment, unstable housing [13,[15][16][17][18].
To our team's knowledge, there are currently no formative studies that specifically examine PrEP implementation indicators among Filipina transfeminine populations [19]. Given this need, the purpose of our exploratory study is to examine prevalence as well as social barriers and opportunities related to outcomes along the PrEP continua, particularly awareness, discussion among friends and interest in taking LAI-PrEP.

Study sample and procedures
We utilized the STROBE checklist for reporting crosssectional study (Supporting Information File, Table S1). This is a secondary data analysis of Filipina transfeminine respondents (n = 139) from the #ParaSaAtin project, a crosssectional self-reported online survey conducted between June 2018 and May 2019. Full study procedures are described elsewhere [20]. Briefly, the study used online convenience sampling recruitment strategies, which included social media advertisements, and online social groups (e.g. Facebook, Twitter) hosted by local HIV community-based organizations and transgender communities in the Philippines. Participants enrolled in the study self-reported to be: 18 years or older, transfeminine (i.e. have a gender identity along the transfeminine spectrum, such as women, trans women and with sex assigned at birth as male), had condomless sex within the past year, currently living in Metro Manila and Central Visayas, and demonstrated English and consent comprehension via a brief cognitive screening form. The survey lasted between 20 and 25 minutes, and participants received P 300 ($5.85 USD) for completing the survey. Electronic, written consent forms were obtained from all participants in this study.

Demographic factors
All participants reported their gender identity as woman (woman, trans woman, transfeminine and have sex assigned as birth as male). We asked participants about their age, current living location, highest education attained, past year income, religious affiliation and sexual orientation.

Social and community-level factors
We assessed whether participants had a history of homelessness (yes vs. no), were currently unemployed (yes vs. no) or recently (within the past 4 months) had engaged in sex work themselves (yes vs. no). We adapted Lippman and colleagues' social cohesion scale [21], which is comprised of 9 items with 5-point Likert responses (from strongly agree = 1 to strongly disagree = 5). Summed scores (Cronbach = 0.87) were dichotomized into low versus high social cohesion. We then assessed social participation in general and lesbian, gay bisexual, and transgender (LGBT) community activities by adapting Fonner and colleagues' 4-item social participation scale [22]. Similarly, summed scores (Cronbach = 0.75 for general social participation and Cronbach = 0.76 for LGBT social participation, respectively), were dichotomized into low versus high social participation. Lastly, we adapted Haggerty and colleagues' 6-item healthcare accessibility scale [23]. Summed scores (Cronbach = 0.93) were also dichotomized into poor/fair versus good/excellent accessibility.

HIV and other healthcare indicators
We asked if participants have current health insurance, ever took hormones for gender affirmation, ever had surgery for gender affirmation or experienced healthcare discrimination due to their transgender identity. We also asked about their healthcare history with HIV services, including if they ever had an HIV test, discussed HIV with their provider or sexual partner, or avoided HIV services due to: cost, distance to/from a healthcare facility, their transgender identity or healthcare facility's lack of LGBT anti-discrimination policy. All responses were either yes or no. We also used the International AIDS Questionnaire to assessed participants' HIV knowledge (Cronbach = 0.84), and scored responses were dichotomized into low versus high HIV knowledge categories [24].

PrEP awareness, PrEP discussion among trans friends and interest in LAI-PrEP (outcomes)
We adapted our PrEP questions from Restar and colleagues [12]. Participants were first provided a brief definition of PrEP: "One way to fight HIV is called PrEP, which stands for pre-exposure prophylaxis. PrEP works by giving HIV-negative people HIV drugs to keep them from getting HIV." We then asked participants if they "have heard of HIV-negative people taking HIV medication before sex because they thought it would lower their chances of getting HIV (also known as PrEP)?" We then asked if they had PrEP discussions among their trans friends (yes vs. no). Lastly, we assessed interest in LAI-PrEP by asking, "If the possibility of having a long-lasting injectable drug to prevent HIV ('injectable PrEP') was available, would you be interested in taking it?" and 3-item Likert scale responses were recoded to aid interpretability of our logistic models, and were dichotomized to very interested versus somewhat/not at all interested.

Data analysis
We conducted descriptive (frequencies, percentages) and bivariate analyses to examine the distribution and independent relationships, respectively, between our exposures and outcomes: PrEP awareness, PrEP discussion and interest in LAI-PrEP.
To examine characteristics associated with our outcomes (PrEP awareness, PrEP discussion and interest in LAI-PrEP), we performed a series of multivariable logistic regression analyses. Given the exploratory nature of this study, we utilized lasso regression procedures to identify the key variables per outcome [25]. All variables that were selected via the lasso procedure were included in the final adjusted model per outcome. Additionally, given the modest sample size, we used non-parametric bootstrapping procedures using 100 iterations to reduce Type 1 error per model and estimate confidence intervals [26]. Alpha for analyses was set to <0.05 a priori, and all analyses were conducted using StataMP version 17.0.

Sample characteristics
In our sample characteristics (Table 1), the proportion of our sample demographics, social and community-level factors, HIV and healthcare indicators by our main outcomes are shown.

PrEP outcomes
As shown in Figure S1, 53% of the sample were aware of PrEP, 39% had discussed PrEP with their trans friends. For LAI-PrEP, a total of 73% of the responses were very interested. A total of 23.74% of the participants were somewhat interested and 3.6% were not at all interested in LAI-PrEP.

D I S C U S S I O N
Our study is a compelling national context for understanding the implementation factors to optimize LAI-PrEP, based on the concentrated growth in HIV diagnoses among transfeminine people in the Philippines and the country's stated commitment to providing PrEP to priority populations.
Notably, all three PrEP outcomes were associated with discussing HIV services with a healthcare provider, reflecting a critical point for future implementation of provider-based intervention. Although the Philippines' Health Department has articulated a commitment to providing access to PrEP mediations for key populations in the Philippines, efforts are needed to train providers in delivering inclusive, non-discriminatory care, including PrEP, for trans populations.
Overall, just over half of the sample had heard of PrEP. This low level of awareness might reflect the very recent approval of PrEP as part of the Philippines government's medical formulary, with a potential for higher awareness over time. Of note, those who identified as being Catholic also had lower PrEP awareness, suggesting a need to explore the possible roles of stigma and religion as contributors to HIV prevention and risk in this predominantly Catholic setting.
Even fewer participants (39%) had ever discussed PrEP with their friends. Social communication about PrEP has proven to be a challenge in many settings due to PrEPrelated stigma in many parts of the world [7]. Our findings indicated that prior experience of gender-based discrimination in a healthcare setting was negatively associated with PrEP discussion among trans friends. This suggests a need for interventions and support systems that counteract internalized stigma and shame, for example, based on negative healthseeking experiences, and that empower transfeminine people with comfort in openly discussing PrEP as an option for HIV prevention with their peers, particularly youths.
The majority of the sample reported being very interested in LAI-PrEP thereby indicating a target for future intervention development around this modality. Notably, being very interested in LAI-PrEP was more strongly endorsed by those who had previously discussed HIV services with a sexual partner, suggesting an opportunity for couples-involved strategies to promote this modality as a strategy to promote sexual safety and satisfaction within relationships. Moreover, similar to our previous findings in daily oral PrEP among Filipina transfeminine adults [14], the current study findings also highlight the role of providers in creating gender-affirming PrEP systems. Specifically, interactions within healthcare clinics can influence PrEP outcomes such that patients who experience negative interactions (e.g. discrimination) are more likely to report lower PrEP awareness, whereas those who are able to discuss HIV services are more likely to be interested in LAI-PrEP, as reflected by the findings in this study. Additionally, being very interested in LAI-PrEP was also stronger among those based outside of Metro Manila, suggesting the geographic appeal of this long-acting modality among those who might not have proximity to the nation's most resourced hospital and public health settings. Leveraging innovative strategies and lessons learned from the Philippines' local community-based organizations' responses to delivering HIV services via telehealth in light of the recent COVID-19 pandemic could be promising to integrate into future LAI-PrEP programming [27].
Lastly, our study only examined three PrEP outcomes, and future studies must expand the scope to other outcomes along the PrEP continua (e.g. awareness, uptake, adherence and retention) [28].

Limitations
This study is limited in its transferability to other settings in the Philippines mainly due to our recruitment focus and eligibility criteria. For instance, our sample may not capture the diversity of trans communities in the Philippines, particularly those who do not have access to the internet, are not living in the study's recruited areas or transmasculine and nonbinary adults who are also part of trans communities [29]. Due to the cross-sectional nature of this study's data collection design, we are unable to ascertain temporal patterns. We also deployed the survey in English, biasing our sample to those who can comprehend this language. Moreover, due to a lack of clinical guidelines for PrEP at the time this survey was conducted, we did not restrict our sample based on PrEP eligibility indicators (e.g. sexual history, serodiscordant partnerships, HIV status), as such our estimate for PrEP interest may be lower. This study lacked to incorporate new educational materials of long-acting PrEP that refers to other options for modalities (e.g. implant, injectable) and other important attributes like injection sites (e.g. gluteal, arm) or clinic sites (e.g. HIV clinic, primary care clinic, gender clinic), a point for future research.

C O N C L U S I O N S
This study provides important foundational work for understanding how LAI-PrEP may fit into the appropriate HIV prevention infrastructure among Filipina transfeminine adults. Building upon these nascent findings, we encourage future work on these fronts, especially moving beyond just research and policy goals and ensuring that other efforts actively engage with community-based organization and their aims and needs. In doing so, the Philippines' HIV response can continue to build towards improvements in equity among transfeminine adults and other impact sub-populations, an important and essential goal.

S U P P O R T I N G I N F O R M AT I O N
Additional information may be found under the Supporting Information tab for this article: Table S1: STROBE ("STrengthening the Reporting of OBservational studies in Epidemiology") Statement and Checklist. Figure S1: PrEP awareness, PrEP discussion among trans friends and very interested in long-acting PrEP among Filipina transfeminine adults (n = 139). This bar graph figure shows that 53% of the sample were aware of PrEP, 39% had discussed PrEP with their trans friends. For LAI-PrEP, a total of 73% of the responses were very interested. A total of 23.74% of the participants were somewhat interested and 3.6% were not at all interested in LAI-PrEP.